An existing cold crucible induction melter which uses an induction heating method so as to heat and melt radioactive waste, general industrial waste, ceramic materials, metal materials, or the like employs a water cooled pipe or a water cooled segment inside an induction coil.
The existing cold crucible induction melter is configured such that an induced current is generated in water cooled segments due to a high frequency current applied to an induction coil and an induced current is generated in a molten material in the CCIM due to an electromagnetic field formed between the water cooled segments to heat the molten material due to Joule's effect. In this case, the induction coils are positioned outside the water cooled segments and spaced apart by a constant interval from each other to allow an RF current to only flow therethrough.
The existing techniques related to the CCIM in which the water cooled segments are positioned inside the induction coils and spaced apart by an interval from each other are disclosed in German Patent No. 518,499, and U.S. Pat. Nos. 3,223,519, 3,461,215, 4,058,668, 6,144,690 and 6,613,291.
However, the existing CCIMs are disadvantageous in that the water cooled segments positioned inside the induction coils consume a lot of electrical energy.
Also, in the case of the existing CCIMs, the induction coils are mostly installed horizontally and designed to mainly focus on the melting of molten materials, but they do not include a function to facilitate discharge of the molten materials.
The existing CCIMs employ a principle that a sliding door is installed at a molten material discharge hole and when the sliding door is opened, heat of the molten material is transferred and after an elapse of a predetermined time, the molten material is discharged to a lower side. However, the CCIMs employing the above principle have a problem in that since the temperature of the molten material is lowered while the molten material is discharged, ceramics or metals having a high melting point may be partially solidified and thus flowability is reduced to not smoothly discharge the molten material.
Another method to discharge a molten material is that a sealed Inconel tube on which an induction coil is wound is used as a discharge tube, and the molten material is discharged by heating the Inconel tube. However, this method has a limitation in discharging metals (e.g., a group of noble metals, etc.) having a higher melting point than the Inconel tube.